Aircraft: EMB ERJ 170/175 ER/LR
Phase of flight: Parked
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy

I; Mechanic X; at Air Carrier X; [working] as an Airframe/Powerplant (A/P) Mechanic; was instructed by my Lead Mechanic that he wanted me to address an existing MEL on an ERJ-170 aircraft. I was handed the part and informed that I was to attempt to clear an existing Mel. I printed applicable documents and reviewed the task; grabbed a few tools and left out for the ERJ-170; to clear the MEL. Soon after I arrived at the aircraft; I removed the cockpit door panel to bring it out of the plane into a better lit work environment. The aircraft was parked just outside of our Maintenance office so I brought the part and panel back into the shop to change the spring guard located over the cockpit Door Lock Switch. I began to change the spring. I removed the face (cover) of the cockpit door panel; removed the button from its housing to reveal the two hex-head screws that had to be rotated to free the housing that secured the spring guard to the push button assembly. I worked at the small tabs for a bit and another task came up. Hard to recall the second task; but it was something small; rushed and distracting. To my best recollection; it may have been an [aircraft] taxi move where myself and another taxi qualified Mechanic had to reposition another one of our terminating planes (often referred to as over-nighters). Upon my return back to the office I had other paperwork from earlier jobs still incomplete; the in-progress task I left behind when I left the office [earlier]. I picked back up the removal and replacement of the cockpit door lock spring guard for the ERJ-170 aircraft. I finished the install of the spring guard and put the panel back together so I could install the panel back into the airplane. After installing the panel back into the ERJ-170; I performed an Operational Test of the cockpit Auto Door Locking mechanism via the push button on the cockpit door panel. I looked at the functionality of the new spring guard and noted the guard moved smoothly and resiliently; springing back to its guard position. I did not note the orientation of the guard after reinstalling the panel to the airplane. Logbook was signed-off applicably and airplane was dispatched for the next day of scheduled flights. Improper orientation of cockpit door lock spring guard [was later noted].Suggestions:Repeatedly overworked; understaffed and driven to dangerous limits. A constant demand of rush; rush; rush. Phones ringing off the hook; being dispatched by both my Air Carrier Maintenance Operations to performed contract maintenance on two other air carriers and by our [affiliate] Air Carrier Y's Maintenance Operations for contract work on a third major air carrier; with both entities unaware of the demands of the other. Often causing us to be pulled from one plane to the next without completing the previous tasks [already] in-progress. Nothing short of mass confusion. Unsatisfactory lack of communication between departments; each day. Our workloads seem to continue to grow; but our relief as technicians is still non-existent. Time and time again we are one; two; even three mechanics down with insufficient relief. Overtime is a very big issue I have over heard many; many times. So bad that the fresh co-workers that we can use; we don't; due to fear of exhausting allowed budgets for manpower. Honestly and quite frankly; we cannot continue this way. Many corners are cut to meet these heavy demands and dreadfully I feel more injuries and violations are to come. I will go as far to say that I have seen over-stressed and fatigued mechanics explode in rage at other mechanics which only exacerbates our already unstable; highly dangerous work environment. At the same time technicians are worked to the point of illness. Frequent 'out sick calls'; leaving us further understaffed and continuing a cycle of under-manned / over-tasked situations. I feel my direct supervision and Management are frowned upon for attempting to provide us with adequate coverage. Supervisors and Lead mechanics have expressed; both around and directly to me; their concerns of negative actions on both our Manager and our Station for blowing overtime numbers; yet our work loads and individual demands become increasingly more severe. I feel that this is a very dangerous practice - to work aircraft Maintenance personnel to the point of mental and physical exhaustion and continue to expect them to perform at peak levels. Honesty. With the way we are constantly hammered and run into the dirt; I am seriously surprised more incidents don't occur at our station. My scheduled shift and [days working] are Mid-week; early afternoons until after midnight. Very seldom do I get to leave as scheduled. I checked one of my time cards and on it; out of a two week tally; I was released from my shift on-time only once that pay period. Normally it's more along the lines of two to four hours later). As mechanics; we have little to no say so in the matter of remaining past shift. I continue to see myself and my fellow co-workers driving in to work like zombies; sleep-deprived and for lack of better words 'walking time-bombs'. Over and over we make countless mistakes; mostly small and immediately corrected; but we waste a lot of time re-working mistakes or ineffectively troubleshooting faults due to our brains and bodies simply reaching their cut-off. Stumbling through the work day with impaired awareness and poor concentration. Then; having to drive home while uncontrollably nodding off and swerving. Some of us have already been pulled over by local authorities for displaying these signs of impairment on the roads. Often times it is a fight to make it home and I have had to sleep in my vehicle several times because I was unsafe to drive anywhere. Another co-worker faced similar difficulties having had to pullover and rest; unable to drive home after extended shift work. One night; I almost rear-ended a semi-truck while in-route back to work after working long hours. Enough is enough. [An aviation magazine had a recent issue with a headline describing] Aircraft Maintenance Fatigue as a major threat to the aviation industry; stating that medical studies reveal that after 24-hours without sleep the average person has been found to be just as impaired as a drunk driver. Driving Under the Influence (DUI's) kill people and if we are messed up as drunk drivers; the question is what condition are we leaving our mechanics in at the time of dismissal? And in what condition are they returning to work the following day? [Flight] crew members time out; and have to go on rest before returning to work. Are we not as important to the operation? And if so; why are we not held to similar standards? Why are these policies not being enforced? A Mechanic walking into the wing of an airplane; leaving in an ambulance. Another slicing his hand open; and then rushed to the hospital; taxi errors and aircraft damage during movement; incorrect tools and company equipment left on aircraft in a rush to the next aircraft. How is this legal or deemed in good practice of safety? We are trusted to protect the lives of hundreds of passengers and crew members each day. Millions of dollars of equipment and hundreds of lives 'daily'; all depending on us and our flawless performance. We are setting ourselves up for failure. I believe some of these problems can be easily dampened if not completely prevented all together if we re-key our sights to protect the most important product - people; both traveling inside and working on our valued aircraft. I understand that this is a prime example as to the necessity of a safety reporting program; for many of us share the same fears and concerns about this unsafe work environment. Hopefully this warrants a visit to ZZZ; to see first-hand the Operations that take place; the time cards of our staff. Please ask them about shift hours; rest; scheduled report times and extended durations of shifts and the conditions surrounding. Hopefully this issue will be addressed as a high priority to begin seeking out new resolutions for this ongoing threat. An Aircraft Maintenance Technician (AMT) reports how the effects of understaffed Maintenance personnel and excessively long work hours on himself and his co-workers contributes to fatigue; impaired awareness and poor concentration.